A discrimination measurement detector suitable for multi-radiation environment

Abstract

The present invention relates to the field of detector technology, and in particular to a discrimination measurement detector suitable for multi-radiation environments. The detector comprises a scintillator, a photodetector array, a readout circuit board, a signal output terminal, a power supply terminal, a housing, a detection surface, and a base. The scintillator and the photodetector array are placed in the housing, and the scintillator and the photodetector array are coupled and connected from the side. The detection surface closes the housing from the top, and the readout circuit board closes the housing from the bottom. The readout circuit board is placed on the base, and a signal output terminal and a power supply terminal are provided at the bottom of the base. The detector has a simple structure and can be used to measure β-γ mixed fields and realize layered signal derivation. Compared with the traditional structure using PMT, the detector has low voltage, is more compact and flexible, and is insensitive to magnetic fields. Signals from three layers of scintillators can be obtained simultaneously, providing technical support for the future use of multi-path coincidence measurement of β-γ mixed fields.

Description

Technical Field

[0001] The present invention relates to the field of detector technology, and in particular to a discrimination and measurement detector suitable for a multi-radiation environment. Background Art

[0002] With the development of my country's nuclear energy industry, the use of radioactive materials has become increasingly frequent, and the total amount of high-radioactive materials has increased dramatically. Therefore, during nuclear research and application, the radiation risks posed by radioactive materials to operators and the environment must not be ignored. Beta and gamma radiation are common in nuclear workplaces, and both are always present simultaneously. This radiation field is known as a mixed beta-gamma field. To ensure the safety of operators, the public, and the environment, beta-gamma radiation dose monitoring and protection must be implemented during the development and utilization of nuclear energy.

[0003] Currently, research groups both domestically and internationally have reported various principles for distinguishing and measuring different types of energetic particles in mixed fields (α, β, n, and γ), including pulse shape discrimination, multi-detector-multi-PMT, and multi-detector-single-PMT methods. Pulse shape discrimination uses a single detector element to discriminate between different particles by exploiting differences in the ionization density (generated pulses) of the particles within the detector material. Examples include rise time discrimination, constant time discrimination, and constant ratio discrimination. Multi-detector-multi-PMT uses multiple detector elements, each with its signal read by an independent signal measurement unit. This method primarily leverages the differences in signal generation between the detector elements, summing the output signals by time coincidence and energy to determine the particle's irradiation depth (shallow for α particles, deep for γ particles), thereby enabling particle identification and measurement. Multi-detector-single-PMT utilizes multiple detector elements arranged sequentially, with different particles experiencing varying probabilities and proportions of energy deposition within each detector layer. Finally, the presence of signal output from each detection element is measured and the ratio of signal intensities is analyzed to achieve particle identification and collect energy spectrum information. This particle identification device consists of multiple scintillators with different luminescence decay times optically coupled to a photomultiplier tube (PMT) to form a detector.

[0004] Existing detectors include the following types: 1. Scintillator + PMT coupling: This is a conventional detector probe fabrication method, such as directly coupling a plastic scintillator to a photomultiplier tube (PMT) with an optical coupling agent directly applied to the plastic scintillator. 2. Scintillator + light guide + PMT coupling: This is also a conventional probe fabrication method. For example, NaI(Tl) deliquesces and cannot be directly coupled to a PMT, requiring an additional light guide layer. 3. Scintillator + wave-shifting fiber coupling: A groove is typically cut in the scintillator surface, and an optical fiber is embedded within the scintillator surface. However, the PMTs used in these "scintillator + PMT coupling" and "scintillator + light guide + PMT coupling" methods require a high voltage of several hundred volts. The PMTs are not suitable for collecting the signals generated by each scintillator layer, and three PMTs are required, which is very expensive and leads to high costs. The "scintillator + wave-shifting fiber coupling" method suffers from low collection efficiency, and the wave-shifting fiber is very expensive. Therefore, all of the above existing detector probes suffer from similar issues, such as low efficiency and time consumption.

[0005] In response to the above technical problems, the present invention provides a discrimination measurement detector suitable for multi-radiation environments, involving technologies that combine nuclear detection, nuclear electronics and optical signal collection. It targets a new β-γ mixed field discrimination measurement method (this method requires collecting the optical signals of each layer of scintillator separately) and there is no mature probe processing and manufacturing method. Through theoretical simulation calculation and processing, an actual detector probe is produced. The final actual measurement results show that this method can obtain actual and effective detector signals. Summary of the Invention

[0006] The primary purpose of the present invention is to provide a discrimination measurement detector suitable for a multi-radiation environment, comprising a scintillator 1, a photodetector array 2, a readout circuit board 3, a signal output terminal 4, a power supply terminal 5, a housing 6, a detection surface 7, and a base 8. The scintillator 1 and the photodetector array 2 are placed in the housing 6. The scintillator 1 comprises a first layer of scintillators 101, a second layer of scintillators 102, and a third layer of scintillators 103 arranged from top to bottom. The photodetector array 2 comprises a linear array SiPM detector C201, a linear array SiPM detector B202, and a linear array SiPM detector A203 arranged from top to bottom, which are coupled to the three layers of scintillators from the side respectively; the first layer of scintillators 1 01 is provided with a detection surface 7 at the top, and a shell 6 is sealed from the top surface. The readout circuit board 3 seals the shell 6 from the bottom surface. The readout circuit board 3 is placed on the base 8. The bottom of the base 8 is provided with a signal output terminal 4 and a power supply terminal 5. The signal output terminal 4 includes a signal output C401, a signal output B402 and a signal output A403, which respectively output signals of the detector array 2 with the same identification. The readout circuit board 3 provides a bias voltage to the photodetector array 2 through a boost circuit, and pre-amplifies, bias-adjusts, and pulse-shapes the electrical signal output by the photodetector array 2 and outputs it to the signal output terminal 4. The readout circuit board 3 is provided with multiple potential screws for adjusting the voltage.

[0007] Preferably, the first layer scintillator 101 and the second layer scintillator 102 are plastic scintillator crystals, and the third layer scintillator 103 is CsI(Tl) scintillator crystals.

[0008] Preferably, the area of ​​the first scintillator layer 101, the second scintillator layer 102 and the third scintillator layer 103 is 75mm×75mm, the thickness of the first scintillator layer 101 is 0.5mm, the thickness of the second scintillator layer 102 is 18mm, and the thickness of the third scintillator layer 103 is 20mm.

[0009] Preferably, the photodetector array 2 is an array composed of 1×13 SiPM single chips, and the size of a single SiPM chip is 6mm×6mm.

[0010] Preferably, the shell is a 2mm aluminum shell.

[0011] Preferably, the six surfaces of the first scintillator layer 101, the second scintillator layer 102 and the third scintillator layer 103 are polished, and except for the light collecting surface, the other parts are coated with a TiO2 diffuse reflection layer and wrapped with a 20 μm thick aluminized polyester film.

[0012] Preferably, screws are used to fix the various components on the base.

[0013] Preferably, the power supply terminal 5 is a LEMO-3PIN, using a ±12V DC power supply.

[0014] Preferably, the boost circuit changes the bias voltage applied to the linear array SiPM detector A203, the linear array SiPM detector B202 or the linear array SiPM detector C201 by adjusting the potential screw of the boost circuit module, and changes the gain of the linear array SiPM detector A203, the linear array SiPM detector B202 or the linear array SiPM detector C201, and the adjustment range is 25.2V to 30.7V.

[0015] Preferably, the baseline of the pulse signal of the output channel of the linear array SiPM detector A203, the linear array SiPM detector B202 or the linear array SiPM detector C201 is adjusted respectively by adjusting the potential screw of the bias adjustment module, and the adjustment range is ±5V.

[0016] Compared with the existing technology, the beneficial effects of the present invention are: the present invention provides a discrimination measurement detector suitable for multi-radiation environments. The detector has a simple structure, can be used to measure β-γ mixed fields, and can realize layered signal derivation. Compared with the traditional structure using PMT, it has low voltage, smaller and more flexible volume and is insensitive to magnetic fields. It can simultaneously obtain signals from three layers of scintillators, providing technical support for the future use of multi-path coincidence measurement of β-γ mixed fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of a discrimination measurement detector suitable for multi-radiation environments

[0018] Figure 2 Conceptual diagram of a discriminative measurement detector suitable for multi-radiation environments

[0019] 1. Scintillator; 101. First scintillator layer; 102. Second scintillator layer; 103. Third scintillator layer; 2. Photodetector array; 201. Linear array SiPM detector C; 202. Linear array SiPM detector B; 203. Linear array SiPM detector A; 3. Readout circuit board; 4. Signal output terminal; 401. Signal output C; 402. Signal output B; 403. Signal output A; 5. Power supply; 6. Housing; 7. Detection surface; 8. Base

[0020] Figure 3 Appearance of a discrimination measurement detector suitable for multi-radiation environments

[0021] Figure 4 High voltage adjustment and bias adjustment potentiometer distribution

[0022] Figure 5The output signals of the three layers of scintillators are

[0023] Figure 6 The actual measured signals of the three channels DETAILED DESCRIPTION

[0024] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0026] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0027] It is well known to those skilled in the art that a plurality of potential screws are disposed inside the circuit board for adjusting the voltage.

[0028] Example 1: A structure of a discrimination measurement detector suitable for multi-radiation environments

[0029] like Figure 1-3As shown, the present invention provides a discrimination measurement detector suitable for a multi-radiation environment, comprising a scintillator 1, a photodetector array 2, a readout circuit board 3, a signal output terminal 4, a power supply terminal 5, a housing 6, a detection surface 7 and a base 8. The scintillator 1 and the photodetector array 2 are placed in the housing 6. The scintillator 1 comprises a first layer of scintillators 101, a second layer of scintillators 102 and a third layer of scintillators 103 arranged from top to bottom. The photodetector array 2 comprises a linear array SiPM detector C201, a linear array SiPM detector B202 and a linear array SiPM detector A203 arranged from top to bottom, which are coupled to the three layers of scintillators from the side. The first layer of scintillator 101 is provided with a detection surface 7 on the top, and the shell 6 is sealed from the top. The readout circuit board 3 is sealed from the bottom of the shell 6. The readout circuit board 3 is placed on the base 8. The bottom of the base 8 is provided with a signal output terminal 4 and a power supply terminal 5. The signal output terminal 4 includes a signal output C401, a signal output B402 and a signal output A403, which respectively output the signals of the detector array 2 with the same identification. The readout circuit board 3 provides a bias voltage to the photodetector array 2 through a boost circuit, and pre-amplifies, bias-adjusts, and pulse-shapes the electrical signal output by the photodetector array 2 and outputs it to the signal output terminal 4.The first layer scintillator 101 and the second layer scintillator 102 are plastic scintillator crystals, and the third layer scintillator 103 is CsI (Tl) scintillator crystals. The area of ​​the first layer scintillator 101, the second layer scintillator 102 and the third layer scintillator 103 is 75mm×75mm, the thickness of the first layer scintillator 101 is 0.5mm, the thickness of the second layer scintillator 102 is 18mm, and the thickness of the third layer scintillator 103 is 20mm. The photodetector array 2 is an array composed of 1×13 SiPM single chips, and the size of a single SiPM is 6mm×6mm. The shell is a 2mm aluminum shell. The six surfaces of the first layer scintillator 101, the second layer scintillator 102 and the third layer scintillator 103 are polished. Except for the light collection surface, the other parts are coated with a TiO2 diffuse reflection layer and a 20μm thick aluminized polyester film is used. The device is wrapped with a membrane and each component is fixed to the base with screws. The power supply end 5 is a LEMO-3PIN, using a ±12V DC power supply. The boost circuit is to change the bias voltage applied to the linear array SiPM detector A203, the linear array SiPM detector B202 or the linear array SiPM detector C201 by adjusting the potential screw of the boost circuit module, and change the gain of the linear array SiPM detector A203, the linear array SiPM detector B202 or the linear array SiPM detector C201, with an adjustment range of 25.2V to 30.7V. By adjusting the potential screw of the bias adjustment module, the baseline of the pulse signal of the output channel of the linear array SiPM detector A203, the linear array SiPM detector B202 or the linear array SiPM detector C201 is adjusted, with an adjustment range of ±5V.

[0030] Example 2: A readout circuit board for a discrimination measurement detector suitable for multi-radiation environments

[0031] like Figure 4 The figure shows the schematic diagram of the readout circuit board. The power supply port of the readout circuit board and the SMA interface of the output signal are located at the bottom surface of the detector. The power supply requires a ±12V DC power supply. By adjusting the potential screw of the boost circuit, the bias voltage applied to the linear array detector SiPMA / B / C can be changed respectively, thereby changing the gain of SiPM, with an adjustment range of 25.2V to 30.7V. By adjusting the potential screw of the bias adjustment module, the baseline of the pulse signal of the output channel of the three linear array detectors A / B / C can be adjusted respectively, with an adjustment range of ±5V.

[0032] Example 3: Application of a discrimination measurement detector suitable for multi-radiation environments

[0033] The radiation source used in the experimental test was 241 Am, which has α and γ radioactivity, will241 The Am source is placed in front of the detector window, and the outputs of the three layers of scintillators are connected to the oscilloscope respectively.

[0034] Get as Figure 5 The test results shown are as follows: the output pulse width of the first layer of scintillator (output C) and the second layer of scintillator (output B) are both 2μs. Since they are the same type of scintillator, there is only a difference in amplitude. In the figure, the pulse height of output B is 1.2V, and the pulse height of output C is 320mV. The pulse width of the output of the third layer of scintillator (output A) is 5μs because its scintillation light has a longer decay time. In the figure, the pulse height of output A is about 1.8V.

[0035] Figure 6 At a specific moment, the three-channel measurement results show that the pulse height of output A is approximately 600mV, the pulse height of output B is approximately 400mV, and the pulse height of output C is approximately 500mV. These results demonstrate that all three channels can clearly measure signals, providing technical support for future multi-channel coincidence measurements of mixed β-γ fields.

[0036] In summary, the present invention provides a discrimination measurement detector suitable for multi-radiation environments. The detector has a simple structure and can be used to measure β-γ mixed fields. It can realize layered signal derivation. Compared with the traditional structure using PMT, it has low voltage, smaller and more flexible volume, and is insensitive to magnetic fields. It can simultaneously obtain signals from three layers of scintillators, providing technical support for the subsequent use of multi-channel signal coincidence measurement of mixed fields.

[0037] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0038] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A discrimination measurement detector suitable for multi-radiation environment, characterized in that: The invention comprises a scintillator (1), a photodetector array (2), a readout circuit board (3), a signal output terminal (4), a power supply terminal (5), a housing (6), a detection surface (7) and a base (8); the scintillator (1) and the photodetector array (2) are placed in the housing (6); the scintillator (1) comprises a first layer of scintillators (101), a second layer of scintillators (102) and a third layer of scintillators (103) arranged from top to bottom; the photodetector array (2) comprises a linear array SiPM detector C (201), a linear array SiPM detector B (202) and a linear array SiPM detector A (203) arranged from top to bottom, and are respectively coupled to the three layers of scintillators from the side; the first layer of scintillators (101) and the second layer of scintillators (102) are respectively coupled to the three layers of scintillators from the side; 1) A detection surface (7) is provided on the top, and a housing (6) is sealed from the top surface. The readout circuit board (3) seals the housing (6) from the bottom surface. The readout circuit board (3) is placed on a base (8). A signal output terminal (4) and a power supply terminal 5 are provided at the bottom end of the base (8). The signal output terminal (4) includes a signal output C (401), a signal output B (402) and a signal output A (403), which respectively output signals of a photodetector array (2) with the same identification. The readout circuit board (3) provides a bias voltage to the photodetector array (2) through a boost circuit, and pre-amplifies, bias-adjusts, and pulse-shapes the electrical signal output by the photodetector array (2) and outputs it to the signal output terminal (4).

2. The discrimination measurement detector suitable for multi-radiation environment according to claim 1, characterized in that: The first layer of scintillator (101) and the second layer of scintillator (102) are plastic scintillator crystals, and the third layer of scintillator (103) is CsI (Tl) scintillator crystals.

3. The discrimination measurement detector suitable for multi-radiation environment according to claim 2, characterized in that: The areas of the first layer of scintillator (101), the second layer of scintillator (102) and the third layer of scintillator (103) are 75 mm×75 mm, the thickness of the first layer of scintillator (101) is 0.5 mm, the thickness of the second layer of scintillator (102) is 18 mm, and the thickness of the third layer of scintillator (103) is 20 mm.

4. The discrimination measurement detector suitable for multi-radiation environment according to claim 1, characterized in that: The photodetector array (2) is an array composed of 1×13 SiPM single chips, and the size of a single SiPM chip is 6mm×6mm.

5. The discrimination measurement detector suitable for multi-radiation environment according to claim 1, characterized in that: The shell is a 2mm aluminum shell.

6. The discrimination measurement detector suitable for multi-radiation environment according to claim 1, characterized in that: The six surfaces of the first layer scintillator (101), the second layer scintillator (102) and the third layer scintillator (103) are all polished, and except for the light collecting surface, the other parts are coated with a TiO2 diffuse reflection layer and wrapped with a 20 μm thick aluminized polyester film.

7. The discrimination measurement detector suitable for multi-radiation environment according to claim 1, characterized in that: Use screws to fix each component to the base.

8. The discrimination measurement detector suitable for multi-radiation environment according to claim 1, characterized in that: The power supply terminal (5) is a LEMO-3PIN, using a ±12V DC power supply.

9. The discrimination measurement detector suitable for multi-radiation environment according to claim 1, characterized in that: The boost circuit changes the bias voltage applied to the linear array SiPM detector A (203), the linear array SiPM detector B (202) or the linear array SiPM detector C (201) by adjusting the potential screw of the boost circuit module, thereby changing the gain of the linear array SiPM detector A (203), the linear array SiPM detector B (202) or the linear array SiPM detector C (201), and the adjustment range is 25.2V to 30.7V.

10. The discrimination measurement detector suitable for multi-radiation environment according to claim 1, characterized in that: By adjusting the potential screw of the bias adjustment module, the baseline of the pulse signal of the output channel of the linear array SiPM detector A (203), the linear array SiPM detector B (202) or the linear array SiPM detector C (201) is adjusted respectively, and the adjustment range is ±5V.

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